The deadly brain-eating amoeba found in St. Bernard Parish's water has shown up in at five locations in DeSoto Parish, the Louisiana Department of Health and Hospitals announced on Tuesday. DeSoto and St. Bernard were the two parishes that tested positive for the rare Naegleria fowleri amoeba in 2011 after a death in each parish from that bacteria.

The DHH stated that their officials had selected the DeSoto water system to test "out of an abundance of caution" because of that 2011 Naegleria fowleri-related death. A 51-year-old DeSoto Parish woman died after using tap water in a neti pot and becoming infected with the deadly amoeba. A neti pot is a small teapot-shaped container used to rinse out the nose and sinuses with salt water to relieve allergies, colds and sinus trouble. Also that year, a 28-year-old St. Bernard Parish man died after using tap water in a neti pot.

Both DHH and the federal Centers for Disease Control and Prevention officials have acknowledged that the amoeba might have remained in St. Bernard's water system since 2011. And for the past month -- ever since St. Bernard tested positive for the amoeba in its water system after the most recent death -- St. Bernard has been attempting to kill the amoeba by flushing its water system with more and more chlorine.

In September, St. Bernard Parish became the first municipality in the United States to have its treated water system test positive for the rare brain-eating amoeba, according to the CDC. Now, DeSoto has become the second municipal water system in the country to ever test positive in a treated water system.

The 2011 deaths were the first ever recorded in Louisiana involving this microorganism. DHH and CDC testing at that time found the amoeba in the homes of the deceased, but they could not confirm that the amoeba were in the parish water systems themselves.

Because of that, officials assumed that the amoeba was not present elsewhere and instead was confined to the homes' piping. But, since then, CDC has developed a much more intricate method to test for the amoeba.

That new water sampling method uses what’s essentially a dialysis filter that can trap microbes, including parasites, bacteria and viruses. That method filters much more water than the testing used back in 2011.

“It is a lot better,” Louisiana State Epidemiologist Dr. Raoult Ratard said last month after St. Bernard tested positive for the microbe. “In 2011, they had tested something like 1 liter of water (at each site) and now they are testing 100 or so liters. So, you multiply your chances of finding (the amoeba) by more than 100 times.”

People cannot contract the infection by drinking contaminated water, because stomach acid will kill the amoeba, health officials say. Naegleria fowleri infects people by entering the body through the nose.

On Tuesday, DHH announced that the CDC had confirmed the presence of the rare Naegleria fowleri amoeba in DeSoto Parish Waterworks District No. 1, which is one of 14 water systems in the parish.

There are no known current cases of illness related to the amoeba in DeSoto, DHH said. And, beginning on Wednesday, the contaminated water district will flush its system with additional chlorine in an attempt to kill the amoeba, according to DHH.

"We are working closely with the water system and parish officials to ensure that the chlorine levels are increased to a level that will eliminate the risk of exposure to the amoeba," said DHH Office of Public Health Assistant Secretary J.T. Lane.

The contaminated DeSoto water district informed DHH late Tuesday that it would begin a chlorine burn of its water system Wednesday morning to achieve a 1 milligram-per-liter free chlorine residual throughout its system.

Exposure to Naegleria fowleri typically occurs when people go swimming or diving in warm freshwater lakes and rivers. In very rare instances, Naegleria fowleri infections may also occur when contaminated water from other sources, such as inadequately chlorinated swimming pool water or heated tap water less than 116.6 degrees, enters the nose when people submerge their heads or when people irrigate their sinuses with devices such as a neti pot. According to the CDC, people can reduce the risk of a Naegleria fowleri infection by limiting the amount of water going up a person’s nose.